

#include "list.h"
#include <stdio.h>
#include <stdlib.h>

ListNode* CreateListNode(int value)
{
	ListNode* pNode = new ListNode();
	pNode->m_nValue = value;
	pNode->m_pNext = NULL;

	return pNode;
}

void ConnectListNodes(ListNode* pCurrent, ListNode* pNext)
{
	if(pCurrent == NULL)
	{
		printf("Error to connect two nodes.\n");
		exit(1);
	}

	pCurrent->m_pNext = pNext;
}

void PrintListNode(ListNode* pNode)
{
	if(pNode == NULL)
	{
		printf("The node is NULL\n");
	}
	else
	{
		printf("The key in node is %d.\n", pNode->m_nValue);
	}
}

void PrintList(ListNode* pHead)
{
//	printf("PrintList starts.\n");

	ListNode* pNode = pHead;
	while(pNode != NULL)
	{
        printf("%d\t", pNode->m_nValue);
		pNode = pNode->m_pNext;
	}

//	printf("\nPrintList ends.\n");
}

void DestroyList(ListNode* pHead)
{
	ListNode* pNode = pHead;
	while(pNode != NULL)
	{
		pHead = pHead->m_pNext;
		delete pNode;
		pNode = pHead;
	}
}

void AddToTail(ListNode** pHead, int value)
{
	ListNode* pNew = new ListNode();
	pNew->m_nValue = value;
	pNew->m_pNext = NULL;

	if(*pHead == NULL)
	{
		*pHead = pNew;
	}
	else
	{
		ListNode* pNode = *pHead;
		while(pNode->m_pNext != NULL)
			pNode = pNode->m_pNext;

		pNode->m_pNext = pNew;
	}
}

void RemoveNode(ListNode** pHead, int value)
{
	if(pHead == NULL || *pHead == NULL)
		return;

	ListNode* pToBeDeleted = NULL;
	if((*pHead)->m_nValue == value)
	{
		pToBeDeleted = *pHead;
		*pHead = (*pHead)->m_pNext;
	}
	else
	{
		ListNode* pNode = *pHead;
		while(pNode->m_pNext != NULL && pNode->m_pNext->m_nValue != value)
			pNode = pNode->m_pNext;

		if(pNode->m_pNext != NULL && pNode->m_pNext->m_nValue == value)
		{
			pToBeDeleted = pNode->m_pNext;
			pNode->m_pNext = pNode->m_pNext->m_pNext;
		}
	}

	if(pToBeDeleted != NULL)
	{
		delete pToBeDeleted;
		pToBeDeleted = NULL;
	}
}
